Magnetic drill presses have bases which are designed to magnetically couple to a planar surface, such as a ferrous beam. In a typical situation, the base of the magnetic drill press is placed against a surface which will support the press during operation. When activated, an electromagnet, disposed in the base of the drill press, magnetically couples the drill press to the surface. A user will in turn initiate the drilling process using the drill press. At the completion of the drilling process, the electomagnet is deactivated, thereby enabling the user to reposition the drill press for subsequent use.
When the motor driving the drill press is de-energized, there can be considerable inertia remaining in the motor. In most instances, the motor is de-energized by the user while the drill press remains magnetically coupled to the support surface. In some instances, the AC power supplying the drill press and the electromagnet is removed unexpectedly, such as a circuit breaker overload or an inadvertent disconnection of the power cord. As a result, the electomagnet becomes de-energized and remaining motor inertia may cause the drill press to move. In these instances, it is common for the drill bits to be broken.
Therefore, it is desirable to provide an alternate power source for powering electromagnets used in various types of power tools. This section provides background information related to the present disclosure which is not necessarily prior art.